/*
 * Copyright (C) 2010 ARM Limited. All rights reserved.
 *
 * Copyright (C) 2008 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <linux/fb.h>

#include <cutils/log.h>
#include <cutils/atomic.h>
#include <hardware/hardware.h>
#include <hardware/gralloc.h>

#include <GLES/gl.h>

#ifdef MALI_VSYNC_EVENT_REPORT_ENABLE
#include "gralloc_vsync_report.h"
#endif

#include "gralloc_priv.h"
#include "gralloc_helper.h"

// numbers of buffers for page flipping
#define NUM_BUFFERS 2

enum
{
	PAGE_FLIP = 0x00000001,
};

static int fb_set_swap_interval(struct framebuffer_device_t* dev, int interval)
{
	if (interval < dev->minSwapInterval || interval > dev->maxSwapInterval)
	{
		return -EINVAL;
	}

	// Currently not implemented
    return 0;
}

static int fb_post(struct framebuffer_device_t* dev, buffer_handle_t buffer)
{
	if (private_handle_t::validate(buffer) < 0)
	{
		return -EINVAL;
	}

	private_handle_t const* hnd = reinterpret_cast<private_handle_t const*>(buffer);
	private_module_t* m = reinterpret_cast<private_module_t*>(dev->common.module);

	if (m->currentBuffer)
	{
		m->base.unlock(&m->base, m->currentBuffer);
		m->currentBuffer = 0;
	}

	if (hnd->flags & private_handle_t::PRIV_FLAGS_FRAMEBUFFER)
	{
		m->base.lock(&m->base, buffer, private_module_t::PRIV_USAGE_LOCKED_FOR_POST, 
				0, 0, m->info.xres, m->info.yres, NULL);

		const size_t offset = hnd->base - m->framebuffer->base;
                int interrupt;
		m->info.activate = FB_ACTIVATE_VBL;
		m->info.yoffset = offset / m->finfo.line_length;

#ifdef STANDARD_LINUX_SCREEN
#define FBIO_WAITFORVSYNC       _IOW('F', 0x20, __u32)
#define S3CFB_SET_VSYNC_INT	_IOW('F', 206, unsigned int)
		if (ioctl(m->framebuffer->fd, FBIOPAN_DISPLAY, &m->info) == -1) 
		{
			LOGE("FBIOPAN_DISPLAY failed");
			m->base.unlock(&m->base, buffer); 
			return 0;
		}

                // enable VSYNC
                interrupt = 1;
                if(ioctl(m->framebuffer->fd, S3CFB_SET_VSYNC_INT, &interrupt) < 0) 
		{
                    LOGE("S3CFB_SET_VSYNC_INT enable failed");
                    return 0;
                }
                // wait for VSYNC
#ifdef MALI_VSYNC_EVENT_REPORT_ENABLE
		gralloc_mali_vsync_report(MALI_VSYNC_EVENT_BEGIN_WAIT);
#endif
                if(ioctl(m->framebuffer->fd, FBIO_WAITFORVSYNC, 0) < 0) 
		{
                    LOGE("FBIO_WAITFORVSYNC failed");
#ifdef MALI_VSYNC_EVENT_REPORT_ENABLE
			gralloc_mali_vsync_report(MALI_VSYNC_EVENT_END_WAIT);
#endif
                    return 0;
                }
#ifdef MALI_VSYNC_EVENT_REPORT_ENABLE
		gralloc_mali_vsync_report(MALI_VSYNC_EVENT_END_WAIT);
#endif
                // disable VSYNC
                interrupt = 0;
                if(ioctl(m->framebuffer->fd, S3CFB_SET_VSYNC_INT, &interrupt) < 0) 
		{
                    LOGE("S3CFB_SET_VSYNC_INT disable failed");
                    return 0;
                }
#else 
		/*Standard Android way*/
#ifdef MALI_VSYNC_EVENT_REPORT_ENABLE
		gralloc_mali_vsync_report(MALI_VSYNC_EVENT_BEGIN_WAIT);
#endif
		if (ioctl(m->framebuffer->fd, FBIOPUT_VSCREENINFO, &m->info) == -1) 
		{
			LOGE("FBIOPUT_VSCREENINFO failed");
#ifdef MALI_VSYNC_EVENT_REPORT_ENABLE
			gralloc_mali_vsync_report(MALI_VSYNC_EVENT_END_WAIT);
#endif
			m->base.unlock(&m->base, buffer); 
			return -errno;
		}
#ifdef MALI_VSYNC_EVENT_REPORT_ENABLE
		gralloc_mali_vsync_report(MALI_VSYNC_EVENT_END_WAIT);
#endif
#endif

		m->currentBuffer = buffer;
	} 
	else
	{
		void* fb_vaddr;
		void* buffer_vaddr;

		m->base.lock(&m->base, m->framebuffer, GRALLOC_USAGE_SW_WRITE_RARELY, 
				0, 0, m->info.xres, m->info.yres, &fb_vaddr);

		m->base.lock(&m->base, buffer, GRALLOC_USAGE_SW_READ_RARELY, 
				0, 0, m->info.xres, m->info.yres, &buffer_vaddr);

		memcpy(fb_vaddr, buffer_vaddr, m->finfo.line_length * m->info.yres);

		m->base.unlock(&m->base, buffer); 
		m->base.unlock(&m->base, m->framebuffer); 
	}

	return 0;
}

int init_frame_buffer_locked(struct private_module_t* module)
{
	if (module->framebuffer)
	{
		return 0; // Nothing to do, already initialized
	}
        
	char const * const device_template[] =
	{
		"/dev/graphics/fb%u",
		"/dev/fb%u",
		NULL
	};

	int fd = -1;
	int i = 0;
	char name[64];

	while ((fd == -1) && device_template[i])
	{
		snprintf(name, 64, device_template[i], 0);
		fd = open(name, O_RDWR, 0);
		i++;
	}

	if (fd < 0)
	{
		return -errno;
	}

	struct fb_fix_screeninfo finfo;
	if (ioctl(fd, FBIOGET_FSCREENINFO, &finfo) == -1)
	{
		return -errno;
	}

	struct fb_var_screeninfo info;
	if (ioctl(fd, FBIOGET_VSCREENINFO, &info) == -1)
	{
		return -errno;
	}

	info.reserved[0] = 0;
	info.reserved[1] = 0;
	info.reserved[2] = 0;
	info.xoffset = 0;
	info.yoffset = 0;
	info.activate = FB_ACTIVATE_NOW;

#ifdef GRALLOC_16_BITS
	/*
	 * Explicitly request 5/6/5
	 */
	info.bits_per_pixel = 16;
	info.red.offset     = 11;
	info.red.length     = 5;
	info.green.offset   = 5;
	info.green.length   = 6;
	info.blue.offset    = 0;
	info.blue.length    = 5;
	info.transp.offset  = 0;
	info.transp.length  = 0;
#else
	/*
	 * Explicitly request 8/8/8
	 */
	info.bits_per_pixel = 32;
	info.red.offset     = 16;
	info.red.length     = 8;
	info.green.offset   = 8;
	info.green.length   = 8;
	info.blue.offset    = 0;
	info.blue.length    = 8;
	info.transp.offset  = 0;
	info.transp.length  = 0;
#endif

	/*
	 * Request NUM_BUFFERS screens (at lest 2 for page flipping)
	 */
	info.yres_virtual = info.yres * NUM_BUFFERS;

	uint32_t flags = PAGE_FLIP;
	if (ioctl(fd, FBIOPUT_VSCREENINFO, &info) == -1)
	{
		info.yres_virtual = info.yres;
		flags &= ~PAGE_FLIP;
		LOGW("FBIOPUT_VSCREENINFO failed, page flipping not supported");
	}

	if (info.yres_virtual < info.yres * 2)
	{
		// we need at least 2 for page-flipping
		info.yres_virtual = info.yres;
		flags &= ~PAGE_FLIP;
		LOGW("page flipping not supported (yres_virtual=%d, requested=%d)", info.yres_virtual, info.yres*2);
	}

	if (ioctl(fd, FBIOGET_VSCREENINFO, &info) == -1)
	{
		return -errno;
	}

	int refreshRate = 1000000000000000LLU /
	(
		uint64_t( info.upper_margin + info.lower_margin + info.yres )
		* ( info.left_margin  + info.right_margin + info.xres )
		* info.pixclock
	);

	if (refreshRate == 0)
	{
		refreshRate = 60*1000;  // 60 Hz
	}

	if (int(info.width) <= 0 || int(info.height) <= 0)
	{
		// the driver doesn't return that information
		// default to 160 dpi
		info.width  = ((info.xres * 25.4f)/160.0f + 0.5f);
		info.height = ((info.yres * 25.4f)/160.0f + 0.5f);
	}

	float xdpi = (info.xres * 25.4f) / info.width;
	float ydpi = (info.yres * 25.4f) / info.height;
	float fps  = refreshRate / 1000.0f;

	LOGI("using (fd=%d)\n"
	     "id           = %s\n"
	     "xres         = %d px\n"
	     "yres         = %d px\n"
	     "xres_virtual = %d px\n"
	     "yres_virtual = %d px\n"
	     "bpp          = %d\n"
	     "r            = %2u:%u\n"
	     "g            = %2u:%u\n"
	     "b            = %2u:%u\n",
	     fd,
	     finfo.id,
	     info.xres,
	     info.yres,
	     info.xres_virtual,
	     info.yres_virtual,
	     info.bits_per_pixel,
	     info.red.offset, info.red.length,
	     info.green.offset, info.green.length,
	     info.blue.offset, info.blue.length);

	LOGI("width        = %d mm (%f dpi)\n"
	     "height       = %d mm (%f dpi)\n"
	     "refresh rate = %.2f Hz\n",
	     info.width,  xdpi,
	     info.height, ydpi,
	     fps);

	if (ioctl(fd, FBIOGET_FSCREENINFO, &finfo) == -1)
	{
		return -errno;
	}

    if (finfo.smem_len <= 0)
	{
		return -errno;
	}

	module->flags = flags;
	module->info = info;
	module->finfo = finfo;
	module->xdpi = xdpi;
	module->ydpi = ydpi;
	module->fps = fps;

	/*
	 * map the framebuffer
	 */
	size_t fbSize = round_up_to_page_size(finfo.line_length * info.yres_virtual);
	void* vaddr = mmap(0, fbSize, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
	if (vaddr == MAP_FAILED) 
	{
		LOGE("Error mapping the framebuffer (%s)", strerror(errno));
		return -errno;
	}

	memset(vaddr, 0, fbSize);

	// Create a "fake" buffer object for the entire frame buffer memory, and store it in the module
	module->framebuffer = new private_handle_t(private_handle_t::PRIV_FLAGS_FRAMEBUFFER, fbSize, intptr_t(vaddr),
	                                           0, dup(fd), 0);

	module->numBuffers = info.yres_virtual / info.yres;
	module->bufferMask = 0;

	return 0;
}

static int init_frame_buffer(struct private_module_t* module)
{
	pthread_mutex_lock(&module->lock);
	int err = init_frame_buffer_locked(module);
	pthread_mutex_unlock(&module->lock);
	return err;
}

static int fb_close(struct hw_device_t *device)
{
	framebuffer_device_t* dev = reinterpret_cast<framebuffer_device_t*>(device);
	if (dev)
	{
		ump_close();
		delete dev;
	}
	return 0;
}

int compositionComplete(struct framebuffer_device_t* dev)
{
	unsigned char pixels[4];
	/* By doing a readpixel here we force the GL driver to start rendering
	   all the drawcalls up to this point, and to wait for the rendering to be complete.
	   Readpixel() also reads a dummy pixel, but this is not used. We only use this
	   function here to flush the render pipeline. */
	glReadPixels(0, 0, 1, 1, GL_RGBA, GL_UNSIGNED_BYTE, pixels);
	/* The rendering of the backbuffer is now completed.
	   When SurfaceFlinger later does a call to eglSwapBuffer(), the swap will be done
	   synchronously in the same thread, and not asynchronoulsy in a background thread later.
	   The SurfaceFlinger requires this behaviour since it releases the lock on all the
	   SourceBuffers (Layers) after the compositionComplete() function returns.
	   However this "bad" behaviour by SurfaceFlinger should not affect performance, 
	   since the Applications that render the SourceBuffers (Layers) still get the 
	   full renderpipeline using asynchronouls rendering. So they perform at maximum speed,
	   and because of their complexity compared to the Surface flinger jobs, the Surface flinger
	   is normally faster even if it does everyhing synchronous and serial. 
	   */
	return 0;
}

int framebuffer_device_open(hw_module_t const* module, const char* name, hw_device_t** device)
{
	int status = -EINVAL;

	alloc_device_t* gralloc_device;
	status = gralloc_open(module, &gralloc_device);
	if (status < 0)
	{
		return status;
	}

	private_module_t* m = (private_module_t*)module;
	status = init_frame_buffer(m);
	if (status < 0)
	{
		gralloc_close(gralloc_device);
		return status;
	}

	/* initialize our state here */
	framebuffer_device_t *dev = new framebuffer_device_t;
	memset(dev, 0, sizeof(*dev));

	/* initialize the procs */
	dev->common.tag = HARDWARE_DEVICE_TAG;
	dev->common.version = 0;
	dev->common.module = const_cast<hw_module_t*>(module);
	dev->common.close = fb_close;
	dev->setSwapInterval = fb_set_swap_interval;
	dev->post = fb_post;
	dev->setUpdateRect = 0;
	dev->compositionComplete = &compositionComplete;

	int stride = m->finfo.line_length / (m->info.bits_per_pixel >> 3);
	const_cast<uint32_t&>(dev->flags) = 0;
	const_cast<uint32_t&>(dev->width) = m->info.xres;
	const_cast<uint32_t&>(dev->height) = m->info.yres;
	const_cast<int&>(dev->stride) = stride;
#ifdef GRALLOC_16_BITS
	const_cast<int&>(dev->format) = HAL_PIXEL_FORMAT_RGB_565;
#else
	const_cast<int&>(dev->format) = HAL_PIXEL_FORMAT_BGRA_8888;
#endif
	const_cast<float&>(dev->xdpi) = m->xdpi;
	const_cast<float&>(dev->ydpi) = m->ydpi;
	const_cast<float&>(dev->fps) = m->fps;
	const_cast<int&>(dev->minSwapInterval) = 1;
	const_cast<int&>(dev->maxSwapInterval) = 1;
	*device = &dev->common;
	status = 0;

	return status;
}
